Troubles with Baking Normal Maps
This is a rather common issue with this technique. what is happening:
In order to understand how &quot;bumpy&quot; something with completely different geometry is, blender uses a &quot;third model&quot; called a &quot;cage&quot;. (when it's unchecked, the cage just uses the selected model to make it, with the solidify modifier I presume) the cage shoots rays from itself to both the low and high poly geometry, and compares them both to itself. This is a rudimentary technique though, and fails in some specific cases: notably in acute angles when the cage passes through some geometry that's closer to it than the intended geometry. in a visual sense, this is a simplification, where the blue line is the cage.

(in reality, there's no extra face at the top, or if there is, there's some more geometry smoothing it out a little, and probably extending your issue down the legs a bit because of how the cage contracts at sharp, concave corners!)
notice how parts of the cage will see the &quot;backside&quot; of the model first. Basically, you want the cage to be as small as possible while still providing good results. shrink that .3 to half or less, unless the distance between the sculpted and low poly geometry differ that much- and at that point you should probably consider shrink wrapping the lowpoly to fit the high poly geometry more closely. normals are for making glancing and stark shadows better, not replacing proper geometric shapes big enough to add very noticeable bumps to a silhouette.
use the measurement tool and draw a .3m line on the pants, and visualize how big that cage is- that should assist you in finding the right cage size!